Honeywell Primus 880 Pilot's Manual page 33

PRIMUS 880 Digital Weather Radar System
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1. TURBULENCE CAN ONLY BE DETECTED WITHIN AREAS OF
RAINFALL. THE PRIMUS
SYSTEM CANNOT DETECT CLEAR AIR TURBULENCE.
2. UNDETECTED TURBULENCE CAN EXIST WITHIN ANY
STORM CELL. REFER TO SECTION 5, RADAR FACTS, OF THIS
GUIDE FOR ADDITIONAL INFORMATION.
Selecting the 100, 200, or 300 mile range turns off the turbulence
detection. The /T is deleted from the mode annunciation and variable
gain is engaged if previously selected. Subsequent selection of ranges
of 50 miles or less re--engages turbulence detection.
A description of the turbulence detection capabilities and limitations of
this radar system is given in Section 5, Radar Facts, of this guide.
7 RANGE
The RANGE switches are two momentary contact buttons that are used
to select the operating range of the radar (and LSS if installed). The
system permits selection of ranges in WX mode from 5 to 300 NM full
scale. In the flight plan (FPLN) mode, additional ranges of 500 and
1000 miles are permitted. The up arrow selects increasing ranges,
while the down arrow selects decreasing ranges. One--half the
selected range is annunciated at the one--half scale range mark on the
EHSI.
NOTE: Some Integrated avionics systems incorporate radar range
with the map display range control on a MFD/ND display.
8 GAIN
The GAIN is a single turn rotary control and push/pull switch that is used
to control the receiver gain. When the GAIN switch is pushed, the
system enters the preset, calibrated gain mode. Calibrated gain is the
normal mode and is used for weather avoidance. In calibrated gain, the
rotary portion of the GAIN control does nothing.
When the GAIN switch is pulled out, the system enters the variable
gain mode. Variable gain is useful for additional weather analysis and
for ground mapping. In WX mode, variable gain can increase receiver
sensitivity over the calibrated level to show weak targets or it can
be reduced below the calibrated level to eliminate weak returns.
Operating Controls
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WARNINGS
880 DIGITAL WEATHER RADAR
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